JP2007119874A - Copper based alloy and method for producing copper based alloy - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a copper based alloy having excellent fatigue properties without applying a load to the environment. <P>SOLUTION: Regarding the copper based alloy, its phase is made into a β single phase or into β+α2 phases at high temperature, and the β phase is made into a β' martensite phase at low temperature. The volume fraction of the α phase is 5 to 80%, and the alloy has a composition at least comprising Al and Mn. The alloy preferably has a composition comprising, by weight, 3 to 10% Al, 5 to 20% Mn and ≤10% Ni or Co, and the balance copper (Cu) with inevitable impurities. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a copper-based alloy that does not give a load to the environment but has excellent fatigue characteristics and a method for manufacturing the same, and in particular, for example, a vibration damping device or a seismic isolation device that requires fatigue resistance at high strain and low frequency. The present invention relates to a copper-based alloy useful for a member to be formed and a manufacturing method thereof.

  Conventionally, in order to reduce the shaking of an earthquake, a vibration control device and a seismic isolation device are known which are arranged between a building and the ground supporting the building. These vibration damping devices and seismic isolation devices incorporate not only a rubber body, which is an elastic body, but also a vibration damping alloy for suppressing vibrations caused by shaking. It reduced the shaking of the earthquake and made it difficult to transmit the shaking of the earthquake to the building side.

  However, lead materials are generally used as damping alloys for conventional damping devices and seismic isolation devices from the standpoint of damping characteristics. Substitution with materials began to be considered. In addition, since the yield point of lead is as low as about 5 MPa and soft and may be bent by simple bending deformation, when using lead material as a damping alloy, the surroundings are restrained and shear deformed. There was a need to do.

On the other hand, other general metallic materials other than lead, such as stainless steel, iron, brass, etc., may be used as damping alloys. However, these metallic materials are repeatedly used with high strain that falls within the plastic deformation range. Therefore, these general metal materials are unsuitable as damping alloys for use in damping devices or seismic isolation devices.
Japanese Patent Laid-Open No. 2001-20026

From the above, it has become necessary to develop a metal material having damping characteristics equal to or better than those of conventional damping alloys without giving a load to the environment as a damping alloy used in damping devices and seismic isolation devices. . However, this damping alloy has been required to have excellent fatigue properties that do not easily break even when it is repeatedly deformed at a high strain that falls within the plastic deformation range as described above.
In view of the above facts, an object of the present invention is to provide a copper-based alloy having excellent fatigue characteristics, which does not give a load to the environment, and a method for producing a copper-based alloy having such characteristics.

  The copper-based alloy according to claim 1 is characterized in that, in a copper-based alloy in which an α phase is precipitated in a β ′ martensite phase, the volume fraction of the α phase is 5 to 80%. However, in the β ′ martensite phase includes all martensites induced by heat, stress, etc. in the β phase.

The operation of the copper-based alloy according to claim 1 will be described below.
According to the present claim, the fatigue characteristics of the copper-based alloy are improved by setting the volume fraction of the α-phase to 5 to 80% in the copper-based alloy in which the α-phase is precipitated in the β ′ martensite phase. Thus, a copper alloy having excellent fatigue resistance at high strain and low frequency is obtained.

  Therefore, the copper-based alloy of the present invention has excellent fatigue characteristics that do not easily break even when repeatedly deformed at a high strain that falls within the plastic deformation range. It will be the most suitable damping alloy used in seismic devices. Accordingly, since the fatigue characteristics as described above can be obtained without using a lead material, the copper-based alloy of this claim can be an excellent vibration-damping alloy that does not give a load to the environment. And since it is not a lead material, it is not necessary to use it in the form of shear deformation by restraining the surroundings, and the degree of freedom when used as a damping alloy is also increased.

The operation of the copper alloy according to claim 2 will be described below.
The present invention has the same configuration as that of the first embodiment and operates in the same manner, but further 3 to 10% by weight of Al, 5 to 20% by weight of Mn, 10% by weight or less of Ni or Co, and the balance It has the composition that it has the composition which made Cu into.

  That is, a copper-based alloy having an Al element content of less than 3% by weight cannot form a β single phase region, and if the Al element content exceeds 10% by weight, the copper-based alloy becomes extremely brittle. By containing the Mn element, the composition range in which the β phase can exist is expanded to the low Al side, and the cold workability of the copper-based alloy is remarkably improved. However, if the amount of Mn element added is less than 5% by weight, satisfactory cold workability cannot be obtained, and a β single phase region cannot be formed. On the other hand, if the amount of Mn element added exceeds 20% by weight, sufficient fatigue resistance cannot be obtained.

  Furthermore, the Ni element or the Co element exerts an effect of improving the strength of the copper alloy by solid solution strengthening while maintaining cold workability. However, when the added amount of these elements exceeds 10% by weight, a satisfactory effect cannot be obtained. From the above, in the present claims, the weight percentage of each of the above ranges is the optimum range for the copper-based alloy.

The operation of the copper-based alloy according to claim 3 will be described below.
In this claim, it has the same structure as that of claim 1 and claim 2 and operates in the same manner. Furthermore, when the total alloy is 100% by weight, Ni, Co, Fe, Ti, V, Cr, Si , Ge, Nb, Mo, W, Sn, Sb, Mg, P, Be, Zr, Zn, B, C, Ag and at least one element selected from the group consisting of misch metal in total, 0.001 to It has a configuration of containing 10% by weight.

  That is, the copper-based alloy of this claim is Ni, Co, Fe, Ti, V, Cr, Si, Ge, Nb, Mo, W, Sn, Sb, Mg, P, Be, Zr, Zn, B, C In addition, one or more selected from the group consisting of Ag and Misch metal are further contained. However, if the total content of these additive elements exceeds 10% by weight, the martensite transformation temperature decreases and the β ′ martensite phase becomes unstable. On the other hand, if it is less than 0.001% by weight, the effect of these additive elements becomes poor. Accordingly, the total content of these additive elements is preferably in the range of 0.001 to 10% by weight as described above.

The operation of the copper alloy according to claim 4 will be described below.
The present invention has the same configuration as that of the first to third aspects and operates in the same manner, but further has a configuration in which a spiral coil spring is provided. In other words, since the copper alloy is made into a helical coil spring, it will be more reliably deformed, so when a tensile force or shear force is applied to this copper alloy, the spring constant will be lowered and the damping coefficient will be reduced. Becomes higher and has a greater damping characteristic.

The effect | action of the manufacturing method of the copper type alloy which concerns on Claim 5 is demonstrated below.
When manufacturing the copper-based alloy according to any one of claims 1 to 4, after annealing and cold working the copper-based alloy, the copper-based alloy is heat-treated in a β + α two-phase temperature range. It has a configuration.

  That is, when producing a copper-based alloy, a β ′ + α two-phase structure in which an α phase is precipitated in a β ′ martensite phase matrix is obtained through this procedure. When a two-phase structure is used, high fatigue resistance can be obtained. When the heat treatment temperature is set to 900 ° C. and cooled by water cooling, the metal structure is β single phase and the crystal grains are large, and the fatigue resistance is deteriorated. In addition, when the heat treatment temperature is set to 600 ° C., the metal structure becomes an α phase, and the fatigue resistance is similarly reduced.

  As described above, according to the above-described configuration of the present invention, an excellent effect of providing a copper-based alloy having no fatigue load but excellent fatigue characteristics and a method for producing a copper-based alloy having such characteristics can be provided. Have

An embodiment of a copper alloy and a method for producing the same according to the present invention will be described with reference to FIGS.
The copper-based alloy which is a copper-based twin alloy according to the present embodiment has a β (body centered cubic) single phase or a β + α (face centered cubic) two-phase structure at a high temperature, and the β phase is β ′ martense at a low temperature. It is an alloy which becomes a site phase, has a volume fraction of α phase of 5 to 80%, and has a composition containing at least Al and Mn. Further, as a preferred composition of the copper-based alloy of the present embodiment, it contains 3 to 10% by weight of Al, 5 to 20% by weight of Mn, and 10% by weight or less of Ni or Co, with the balance being 60 to 92%. For example, copper (Cu) and inevitable impurities are used.

  If the Al element content is less than 3% by weight, the copper alloy cannot form a β single phase, and if the Al element content exceeds 10% by weight, the copper alloy becomes extremely brittle. However, the more preferable content of the Al element varies depending on the content of the Mn element.

  That is, by containing the Mn element, the composition range in which the β phase can exist is expanded to the low Al side, and the cold workability of the copper-based alloy is remarkably improved. However, if the amount of Mn element added is less than 5% by weight, satisfactory cold workability cannot be obtained, and a β single phase region cannot be formed. Further, if the amount of Mn element added exceeds 20% by weight, sufficient fatigue resistance characteristics cannot be obtained. Therefore, the preferable Mn content is 5 to 20% by weight.

  Furthermore, the Ni element or the Co element exerts an effect of improving the strength of the copper alloy by solid solution strengthening while maintaining cold workability. However, when the added amount of these elements exceeds 10% by weight, a satisfactory effect cannot be obtained.

  In addition to the elements of the above basic composition, the copper-based alloy of the present embodiment includes Ni, Co, Fe, Ti, V, Cr, Si, Ge, Nb, Mo, W, Sn, Sb, Mg, P, Be, 1 type (s) or 2 or more types selected from the group which consists of Zr, Zn, B, C, Ag, and a misch metal can further be contained.

  The total content of these additive elements is preferably 0.001 to 10% by weight, particularly preferably 0.001 to 5% by weight. That is, when the total content of these additive elements exceeds 10% by weight, the martensite transformation temperature decreases and the β ′ martensite phase becomes unstable. Further, when the total content of these additive elements is less than 0.001% by weight, a satisfactory effect by the additive elements cannot be obtained.

  Here, Ni, Co, Fe, Sn and Sb are effective elements for strengthening the base structure. The preferred contents of Ni and Fe are 0.001 to 3% by weight, respectively. Co also strengthens by precipitation due to the formation of CoAl, but if excessive, it lowers the toughness of the copper-based alloy. The preferable content of Co is 0.001 to 2% by weight. The preferred contents of Sn and Sb are 0.001 to 1% by weight, respectively.

  Ti combines with N and O, which are elements that impede alloy properties, to form oxides and nitrides. When combined with B, boride is formed, contributing to precipitation strengthening. The preferable content of Ti is 0.001 to 2% by weight.

  W, V, Nb, Mo, and Zr have the effect of improving hardness and improving wear resistance. Since these elements hardly dissolve in the alloy matrix, they precipitate as bcc crystals and are effective for precipitation strengthening. The preferred contents of W, V, Nb, Mo and Zr are 0.001 to 1% by weight, respectively.

  Cr is an effective element for maintaining wear resistance and corrosion resistance. A preferable content of Cr is 0.001 to 2% by weight. Si has the effect of improving the corrosion resistance. A preferable content of Si is 0.001 to 2% by weight. Ge is an effective element for raising the martensitic transformation temperature. A preferable content of Ge is 0.001 to 2% by weight.

  Mg removes N and O, which are elements that hinder the alloy properties, and fixes S, which is an inhibitory element, as a sulfide, which is effective in improving hot workability and toughness. It causes segregation and causes embrittlement. A preferable content of Mg is 0.001 to 0.5% by weight.

  P acts as a deoxidizer and has the effect of improving toughness. A preferable content of P is 0.01 to 0.5% by weight. Be has the effect of strengthening the base organization. The preferred content of Be is 0.001 to 1% by weight. The preferable content of Zn is 0.001 to 5% by weight.

  B and C segregate at the grain boundaries and have the effect of strengthening the grain boundaries. The preferred contents of B and C are each 0.001 to 0.5% by weight. Ag has the effect of improving cold workability. The preferable content of Ag is 0.001 to 2% by weight. Misch metal acts as a deoxidizer and has the effect of improving toughness. The preferred content of misch metal is 0.001 to 5% by weight.

  From the above, according to the present embodiment, the copper-based alloy in which the α-phase is precipitated in the β ′ martensite phase, and the volume fraction of the α-phase is set to 5 to 80%. The fatigue characteristics of the alloy are improved, and a copper alloy having excellent fatigue characteristics that does not easily break even when deformed repeatedly at a high strain that falls within the plastic deformation range.

Next, the manufacturing method of the copper-type alloy which concerns on this Embodiment is demonstrated.
The copper-based alloy having the above composition is once melted and cast to produce a billet, and then hot-worked by hot rolling or the like at a temperature of 850 ° C. After that, a plate material is produced by repeating the cycle of heat treatment air cooling, cold working by cold rolling or the like and annealing at 600 ° C. air cooling several times.

  The plate material thus obtained is heated again and heat-treated at a temperature of 700 to 850 ° C. which is a β + α two-phase temperature range, and then cooled by air cooling or water cooling (β ′ + α) two-phase structure. Copper alloy. That is, a copper-based alloy in which an α phase is precipitated in the β ′ martensite phase and the volume fraction of the α phase is 5 to 80% is manufactured. Therefore, in the production of a copper-based alloy, a two-phase structure of β ′ + α in which an α phase is precipitated in a β ′ martensite phase matrix is obtained through the above procedure. When a two-phase structure of '+ α is used, high fatigue resistance can be obtained. By aging at a temperature of 100 to 400 ° C. as required, the martensite transformation temperature can be stabilized or the strength can be increased by age hardening.

Next, although the following examples explain the present invention still in detail, the present invention is not limited to them.
First, a copper-based alloy having a composition of (Cu-17.5Al-8.5Mn) -2Ni (at%) is once melted and then solidified to form a plate-like billet having a length and width of about 100 mm and a thickness of 12 mm. Is made. The billet was then hot rolled to a thickness of 2.5 mm at a temperature of 850 ° C.

  Furthermore, the plate material of thickness 1mm was produced by repeating the cycle which consists of cold rolling and annealing air cooling for 15 minutes at 600 degreeC 3 times. The plate material having a thickness of 1 mm obtained as described above is cut into a test piece and subjected to heat treatment at a temperature of 700 to 850 ° C. for 5 minutes, and then air-cooled or water-cooled (β ′ + α) 2 A copper alloy having a phase structure was produced as an example.

  In this case, when the heat treatment temperature is high, for example, 900 ° C. and cooling is performed by water cooling, the metal structure is β single phase, the crystal grains are large, and the fatigue resistance is deteriorated. Further, when the heat treatment temperature is low, for example, 600 ° C., the metal structure becomes an α phase, and the fatigue resistance is similarly lowered. For this reason, the fact that the temperature range of 700 to 850 ° C. is optimal is supported by these facts.

Next, the results of performing the following repeated bending tests on the test pieces of Examples and Comparative Examples formed by processing the plate material obtained as described above will be described.
First, as a sample, M2052 (Mn alloy), Brass (brass), SUS304 (stainless steel), SUS430 (stainless steel), Pb, Cu, Fe, and other metals are used as comparative examples, and the copper of the above examples. Two types of alloys were produced. Specifically, as a copper-based alloy of the example, after heat treatment at a temperature of 700 to 850 ° C., an air-cooled sample and a water-cooled sample were respectively produced.

  Further, the test piece 1 for testing each sample has a width dimension of 10 mm, a thickness T shown in FIG. 1 of 1 mm, a length L of each of the two straight portions 1A of 40 mm, and a bent portion. The outer diameter D of 1B is formed into a U-shape with 25 mm. Then, a test in which a movable member 4 extending in the left-right direction and reciprocating in the left-right direction is disposed between a pair of fixing members 3 extending in the left-right direction as shown in FIG. Two test pieces 1 were attached to the apparatus 2 and repeated bending tests were performed.

  That is, as shown in FIG. 2A, one of the two straight portions 1 </ b> A of the test piece 1 is fixed to the fixed member 3, and the other straight portion 1 </ b> A is fixed to the movable member 4. In this manner, two test pieces 1 are attached to the test apparatus 2 respectively. Then, the movable member 4 is moved between the state of FIG. 2B and the state of FIG. 2C so that the stroke S corresponding to the surface maximum strain of 4% is ± 25 mm and the frequency is 0.3 Hz. A repetitive bending test was conducted in such a manner that the reciprocating motion was measured as one reciprocation.

  As a result of this repeated bending test, as shown in the graph of FIG. 3, the air-cooled example and the water-cooled example sample have high fatigue resistance, and the sample of the air-cooled example (Cu (Ni) AC) is represented. ) Was bent 1111 times, and the water-cooled example sample (represented as Cu (Ni) WQ) was bent 1000 times.

  In addition, as the graph shown in FIG. 3, the metal of the other comparative example fractured | ruptured with the frequency | count of bending of about dozens of times to 300 times. From the above, it was confirmed by this repeated bending test that the fatigue resistance characteristics of the copper-based alloys of the examples were three times higher than the fatigue resistance characteristics of the samples of the other comparative examples. Further, in the repeated bending test using the U-shaped test piece 1 described above, it can be said that the performance is sufficient if the number of repeated bending until breakage is 500 times or more under the conditions of a maximum surface strain of 4% and a frequency of 0.3 Hz. Also in this respect, it was confirmed that the copper-based alloy of the example had no problem.

  Furthermore, a sample obtained by air-cooling a copper-based alloy having the above composition and a sample obtained by water-cooling a similar copper-based alloy were produced in a plurality of types by changing the heat treatment temperature. That is, samples under seven conditions of 600 ° C., 650 ° C., 700 ° C., 750 ° C., 800 ° C., 850 ° C., and 900 ° C. were prepared as the heat treatment temperature conditions, respectively. Then, each sample was repeatedly subjected to a bending test under the same test conditions as described above using the same test apparatus 2 as described above.

  As a result of this repeated bending test, as shown in the graph of FIG. 4, in the characteristic curve AC of the sample of the air-cooled example, the heat treatment temperature is about 800 ° C., and the number of bendings until breakage reaches a peak of 1000 times or more. In the characteristic curve WQ of the sample of the water-cooled example, the heat treatment temperature was about 750 ° C., and the number of bending until breakage was also a peak of 1000 times or more.

  Accordingly, among the copper-based alloys of the examples heat-treated at a temperature of 700 to 850 ° C., the β ′ phase when the water-cooled sample was heat-treated at about 750 ° C. and the air-cooled sample was heat-treated at about 800 ° C. As a result of this repeated bending test, it was confirmed that the best fatigue resistance can be obtained by a two-phase structure in which α and α phases are mixed.

  Next, the seismic isolation device 10 employing the copper-based alloy of the present embodiment as a damping alloy will be described with reference to FIGS. 5 and 6. As shown in these figures, the upper and lower parts of the seismic isolation device 10 are constituted by connecting plates 12 and 14 each formed in a disc shape. The lower connecting plate 12 is in contact with the ground, and the upper connecting plate 14 is in contact with the lower part of the building.

  Between the pair of connecting plates 12 and 14, a rubber body 16 formed in a cylindrical shape with a circular hole 16A in the center is disposed. The rubber body 16 includes a plurality of rubber rubber rings 18 that are formed in a ring shape and can be elastically deformed, and a plurality of metal metal rings 20 that are formed in a ring shape and maintain rigidity. The structure is arranged.

  On the other hand, the pair of connecting plates 12 and 14 are attached by vulcanization and bonding to the upper and lower ends of the rubber body 16, respectively, and stepped portions are provided in the middle of the pair of connecting plates 12 and 14, respectively. Circular through-holes 12A and 14A having the shape are formed. However, the lid member 30 having a size corresponding to the through holes 12A and 14A and having a flange on the outer peripheral side is fixed to the pair of connecting plates 12 and 14 by screwing with bolts 32, respectively. The through holes 12A and 14A are closed.

  A vibration damping member 26 formed in a cylindrical shape is fitted into the circular hole 16A present at the center of the rubber body 16, and the vibration damping member 26 is provided with copper. A damping alloy 22 formed in the shape of a helical coil spring that can be elastically deformed with an alloy is incorporated. That is, a rubber material is vulcanized and bonded around the damping alloy 22, and the damping alloy 22 is covered with a vulcanized rubber portion 24 formed in a cylindrical shape by the rubber material.

  Next, the operation of the seismic isolation device 10 employing the copper-based alloy of the present embodiment as the damping alloy 22 will be described below. According to the present embodiment, the damping alloy 22 made of a copper alloy, which is an elastically deformable helical coil spring, is covered with the vulcanized rubber portion 24. The seismic isolation device 10 has a structure in which the rubber body 16 is arranged in parallel with the alloy 22.

  Accordingly, according to the seismic isolation device 10 according to the present embodiment, even when an earthquake occurs, the rubber body 16 arranged in parallel with the vibration damping alloy 22 and elastically deformed and the vibration damping alloy 22 The combined action between them reduces earthquake shaking and makes it difficult to transmit earthquake shaking to the building.

  That is, the damping alloy 22 made of the copper-based alloy according to the present embodiment is repeatedly deformed with a high strain so as to enter the plastic deformation region in the event of an earthquake, but even in such a case, it easily breaks. Since it has such excellent fatigue characteristics, it is optimal as a damping alloy used in the seismic isolation device 10.

  On the other hand, the damping alloy 22 used in the seismic isolation device 10 of the present embodiment is formed of a copper-based alloy in a spring shape that can be elastically deformed. Vibration characteristics and fatigue characteristics can be obtained. For this reason, according to the seismic isolation apparatus 10 of this Embodiment, it does not give a load to an environment. And since it is set as the copper-type alloy instead of a lead material, it becomes unnecessary to use it in the form which restrained the circumference | surroundings and carried out the shear deformation, and the freedom degree at the time of using as a damping alloy also becomes high.

  On the other hand, in the present embodiment, since the damping alloy 22 is a spiral coil spring, the damping alloy 22 is more reliably deformed. Therefore, a tensile force or a shearing force is applied to the damping alloy 22. When is added, the spring constant is further reduced and the damping coefficient is increased, so that a better damping characteristic can be obtained. Although the present embodiment has been described based on an example in which Ni is contained in the copper-based alloy, a copper-based alloy containing Co instead of Ni may be used as the damping alloy 22.

  Furthermore, in the said embodiment, although the damping alloy 22 is a helical coil spring, you may make the damping alloy 22 into another structure. Further, in the above embodiment, the rubber material is vulcanized and bonded around the damping alloy 22, but if necessary characteristics are obtained, the rubber material is not used, or a synthetic resin is used instead of the rubber material. The periphery of the damping alloy 22 may be covered. And although the example used for a seismic isolation apparatus was demonstrated in the said embodiment, you may use the copper-type alloy of this invention for a damping device.

It is a front view of the test piece produced with the copper-type alloy etc. which concern on embodiment of this invention. It is a figure which shows the test apparatus which tests the test piece produced with the copper-type alloy etc. which concern on embodiment of this invention, Comprising: (A) is a figure which shows the state which attaches a test piece, (B) is a test apparatus. It is a figure which shows the state which left the movable member of the maximum to the left side, (C) is a figure which shows the state where the movable member of the test apparatus has approached the maximum to the right side. It is a figure which shows the graph each showing the frequency | count to the fracture | rupture of the Example in a repeated bending test, and a comparative example. It is a figure which shows the graph showing the relationship between the frequency | count to a fracture | rupture in a repeated bending test, and heat processing temperature. 1 is an exploded perspective view of a seismic isolation device employing a copper alloy according to an embodiment of the present invention. It is sectional drawing of the seismic isolation apparatus by which the copper type alloy which concerns on embodiment of this invention was employ | adopted.

Explanation of symbols

1 Test piece 2 Test device 10 Seismic isolation device 22 Damping alloy

Claims (5)

  A copper-based alloy in which an α-phase is precipitated in a β 'martensite phase, wherein the volume fraction of the α-phase is 5 to 80%.   The copper-based alloy according to claim 1, having a composition of 3 to 10% by weight of Al, 5 to 20% by weight of Mn, 10% by weight or less of Ni or Co, and the balance being Cu.   When the total alloy is 100% by weight, Ni, Co, Fe, Ti, V, Cr, Si, Ge, Nb, Mo, W, Sn, Sb, Mg, P, Be, Zr, Zn, B, C, 3. The copper-based alloy according to claim 1, further comprising 0.001 to 10 wt% of at least one element selected from the group consisting of Ag and Misch metal.   The copper-based alloy according to any one of claims 1 to 3, wherein the copper-based alloy is a spiral coil spring. A method for producing a copper-based alloy for producing the copper-based alloy according to any one of claims 1 to 4,
After annealing and cold working copper alloy,
A method for producing a copper-based alloy, comprising heat-treating the copper-based alloy in a two-phase temperature range of β + α.

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